linux-kernel - [PATCH v2 02/10] xtensa: clean up exception handler prototypes

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Date:   Thu, 21 Apr 2022 03:10:25 -0700
From:   Max Filippov <jcmvbkbc@...il.com>
To:     linux-xtensa@...ux-xtensa.org
Cc:     Chris Zankel <chris@...kel.net>, linux-kernel@...r.kernel.org,
        Max Filippov <jcmvbkbc@...il.com>
Subject: [PATCH v2 02/10] xtensa: clean up exception handler prototypes

Exception handlers are currently passed as void pointers because they
may have one or two parameters. Only two handlers uses the second
parameter and it is available in the struct pt_regs anyway. Make all
handlers have only one parameter, introduce xtensa_exception_handler
type for handlers and use it in trap_set_handler.

Signed-off-by: Max Filippov <jcmvbkbc@...il.com>
---
Changes v1->v2:

- new patch

 arch/xtensa/include/asm/traps.h      | 14 ++++++--------
 arch/xtensa/kernel/s32c1i_selftest.c |  7 +++----
 arch/xtensa/kernel/traps.c           |  7 ++++---
 3 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/xtensa/include/asm/traps.h b/arch/xtensa/include/asm/traps.h
index fc63217232a4..bfdb0af61b07 100644
--- a/arch/xtensa/include/asm/traps.h
+++ b/arch/xtensa/include/asm/traps.h
@@ -12,6 +12,8 @@
 
 #include <asm/ptrace.h>
 
+typedef void xtensa_exception_handler(struct pt_regs *regs);
+
 /*
  * Per-CPU exception handling data structure.
  * EXCSAVE1 points to it.
@@ -30,15 +32,11 @@ struct exc_table {
 	/* Fast kernel exception handlers */
 	void *fast_kernel_handler[EXCCAUSE_N];
 	/* Default C-Handlers */
-	void *default_handler[EXCCAUSE_N];
+	xtensa_exception_handler *default_handler[EXCCAUSE_N];
 };
 
-/*
- * handler must be either of the following:
- *  void (*)(struct pt_regs *regs);
- *  void (*)(struct pt_regs *regs, unsigned long exccause);
- */
-extern void * __init trap_set_handler(int cause, void *handler);
+xtensa_exception_handler *
+__init trap_set_handler(int cause, xtensa_exception_handler *handler);
 
 asmlinkage void fast_illegal_instruction_user(void);
 asmlinkage void fast_syscall_user(void);
@@ -54,7 +52,7 @@ asmlinkage void system_call(struct pt_regs *regs);
 
 void do_IRQ(int hwirq, struct pt_regs *regs);
 void do_page_fault(struct pt_regs *regs);
-void do_unhandled(struct pt_regs *regs, unsigned long exccause);
+void do_unhandled(struct pt_regs *regs);
 
 /* Initialize minimal exc_table structure sufficient for basic paging */
 static inline void __init early_trap_init(void)
diff --git a/arch/xtensa/kernel/s32c1i_selftest.c b/arch/xtensa/kernel/s32c1i_selftest.c
index 07e56e3a9a8b..8362388c8719 100644
--- a/arch/xtensa/kernel/s32c1i_selftest.c
+++ b/arch/xtensa/kernel/s32c1i_selftest.c
@@ -40,14 +40,13 @@ static inline int probed_compare_swap(int *v, int cmp, int set)
 
 /* Handle probed exception */
 
-static void __init do_probed_exception(struct pt_regs *regs,
-				       unsigned long exccause)
+static void __init do_probed_exception(struct pt_regs *regs)
 {
 	if (regs->pc == rcw_probe_pc) {	/* exception on s32c1i ? */
 		regs->pc += 3;		/* skip the s32c1i instruction */
-		rcw_exc = exccause;
+		rcw_exc = regs->exccause;
 	} else {
-		do_unhandled(regs, exccause);
+		do_unhandled(regs);
 	}
 }
 
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index b6bb5911ec7f..d6b1a0c3e319 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -170,7 +170,7 @@ __die_if_kernel(const char *str, struct pt_regs *regs, long err)
  * Unhandled Exceptions. Kill user task or panic if in kernel space.
  */
 
-void do_unhandled(struct pt_regs *regs, unsigned long exccause)
+void do_unhandled(struct pt_regs *regs)
 {
 	__die_if_kernel("Caught unhandled exception - should not happen",
 			regs, SIGKILL);
@@ -180,7 +180,7 @@ void do_unhandled(struct pt_regs *regs, unsigned long exccause)
 			    "(pid = %d, pc = %#010lx) - should not happen\n"
 			    "\tEXCCAUSE is %ld\n",
 			    current->comm, task_pid_nr(current), regs->pc,
-			    exccause);
+			    regs->exccause);
 	force_sig(SIGILL);
 }
 
@@ -360,7 +360,8 @@ static void do_debug(struct pt_regs *regs)
 
 /* Set exception C handler - for temporary use when probing exceptions */
 
-void * __init trap_set_handler(int cause, void *handler)
+xtensa_exception_handler *
+__init trap_set_handler(int cause, xtensa_exception_handler *handler)
 {
 	void *previous = per_cpu(exc_table, 0).default_handler[cause];
 
-- 
2.30.2